Finish: Overview of the History of Cog Psych

then

Review of Physiological Methods in Cog Psych

Psychology 355: Cognitive Psychology

Instructor: John Miyamoto

04/02/2015: Lecture 01-4

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Outline

• How did cognitive psychology become a major focus within psychology?

Overview of Physiological Methods in Cognitive Psychology

• Single cell recordings of neural activity

• Event-related potentials (ERP)

• Positron emission tomography (PET)

• Functional magnetic resonance imaging (fMRI)

• Example of fMRI applied to localization of perceptual function

Psych 355, Miyamoto, Spr '15 2Overview of History of Cog Psych

3Psych 355, Miyamoto, Spr '15

Overview of the History of Cognitive Psychology

• Precursors to cognitive psychologyo Aristotle, Plato – epistemology, theory of ideas and their relation

to human action

• Experimental psychology begins in 19th century Germanyo Franciscus Donders (response time analysis, method of subtraction)o Hermann von Helmholtz (perception, unconscious inference)o Hermann Ebbinghaus (experimental study of memory)o Wilhelm Wundt (analytic introspection, analysis of conscious experience)

• Behaviorist hiatus in America: roughly 1920 – 1960o During the behaviorist period (1920-1960), cognitive psychology

continued to be studied in Europe.

• Revival of cognitive psychology in America (1950 – 1970)

• 1970 – present: Cognitive psychology plays a major role in psychology pretty much everywhere in the world

Behaviorist Hiatus in America

Done!

4Psych 355, Miyamoto, Spr '15

Behaviorist Hiatus – Roughly 1920 - 1960

• John Watsono Influenced by positivist philosophy.

The goal of science is to predict whatever is observable. o Science should eliminate assumptions about whatever is not observable.

(Questionable)o Consciousness is not observable. Eliminate it from psychological theory.

Anti-introspectionist. o Opposed to theories that postulated unobserved psychological processes

• Clark Hull – Stimulus/Response (S/R) learning model.

• Edwin Guthrie

• B. F. Skinner – Reinforcement theory

• Behaviorism was an American approach to psychology – not so

influential in Europe and elsewhere.

Cognitive Psychology During the Behaviorist Period

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Cognitive Psychology During the Behaviorist Period

• William James (1842 – 1910; cognitive psychology)

• Jean Piaget – genetic epistemology

• Lev Vygotsky – cognitive development and education

• Sir Frederick Bartlett (constructive memory processes)

• Gestalt psychology – Kurt Lewin, Wolfgang Kohler

• The beginnings of the computer revolution. Alan Turing, Norbert Wiener, John von Neumann

Psych 355, Miyamoto, Spr '15 Behaviorism Loses Its Grip on Psychology

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Behaviorism lost its grip on American psychology during the 1960's. Why did this happen?

• Problematic results ♦ Learning without responding:

Rats that are temporarily paralyzed with atropine can learn the layout ofa maze from being wheeled around the maze.

♦ Learning without reinforcement:Rats that explore a maze with no reinforcements show learning of the mazewhen they are later rewarded for running the maze.

Psych 355, Miyamoto, Spr '15 Why Behaviorism Lost Its Grip on Psych - Continuation of this Slide

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Behaviorism lost its grip on American psychology during the 1960's. Why did this happen?

• Problematic results

• Behaviorism couldn’t explain what scientists wanted to understand, e.g., language, perception, attention, reasoning. (Lashley, Chomsky, Miller-Galanter-Pribram).

• Alternative approaches came along that looked more promising. ♦ Structural models, e.g., transformational grammar, genetic epistemology.♦ Computer models, e.g., the General Problem Solver of Newell and Simon.♦ Change of focus to experimentation on human information processing.

• Is it unscientific to postulate unobserved psychological processes in a psychological theory?

Psych 355, Miyamoto, Spr '15 Revival of Cognitive Psychology – Information Processing

8Psych 355, Miyamoto, Spr '15

Revival of Cognitive Psychology: 1950 - 1960

• Alan Newell & Herbert Simon:

Computer models of problem solving

• Noam Chomsky - Grammar of natural language

• Lashley – Neuroscience

• Hubel & Wiesel – Receptive fields in the visual cortex

Cognitive Psychology Since 1960

9Psych 355, Miyamoto, Spr '15

Cognitive Psychology Since 1960

• Experimental cognitive psychology – Emphasizes the behavioral approach

o Perception & Attention, Memory, Language, Reasoning & problem solving, Cognitive development

• Computer modeling of cognitive processes – Usually a mixture of the behavioral and computational approach

• Physiological Approacho Single-cell recordingso PET, fMRI, ERP o Study effects of drugs

END

Behavioral Approach:All dependent measures in a study are observed behavior.

Physiological Approach:All dependent measures in a study are measures of physiological states or physiological responses.

Hybrid Approach (Cognitive Neuroscience): The study attempts to explain behavioral responses, physiological responses, and may include computational modeling of behavior.

Outline – Physiological Methods in Cognitive Neuroscience

• Single cell recordings of neural activity

• Event-related potentials (ERP)

• Positron emission tomography (PET)

• Functional magnetic resonance imaging (fMRI)

• Example of fMRI applied to localization of perceptual function

Psych 355, Miyamoto, Spr '15 10Brief Introduction to Neural Information Processing

11Psych 355, Miyamoto, Spr '15

Brief Introduction to Neural Information Processing

• Structure of a neuron (nerve cell)

• How neurons transmit information

Diagram of Nerve Cell & Info Transmission

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The Parts of a Neuron (Nerve Cell)

Psych 355, Miyamoto, Spr '15

• Cell body or soma – main body of the neuron.

• Dendrites –brushy projections that receive stimulation from other cells.

• Axon – long projection that carries stimulation to other cells.

• Terminal buttons (a.k.a. axon terminals or synaptic terminals) – End of axon where a neurochemical signal is passed to other nerve cells.

Same Slide without the Red Ovals

Next Slide

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The Parts of a Neuron (Nerve Cell)

Psych 355, Miyamoto, Spr '15

• Cell body or soma – main body of the neuron.

• Dendrites –brushy projections that receive stimulation from other cells.

• Axon – long projection that carries stimulation to other cells.

• Terminal buttons (a.k.a. axon terminals or synaptic terminals) – End of axon where a neurochemical signal is passed to other nerve cells.

Enlargement of Synapse

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The Synapse – Point of Contact Between Two Nerve Cells

Psych 355, Miyamoto, Spr '15

Nice pictures of a synapse are available at:

http://www.rnceus.com/meth/Introneurotrans.html

and http://www.educarer.com/brain.htm .

Image downloaded from Wikipedia (1/9/07):http://en.wikipedia.org/wiki/Synapse

Action Potentials are All-of-None

Goldstein (2014), Figure 2.5,p. 30.

15Psych 355, Miyamoto, Spr '15

The Synapse – Point of Contact Between Two Nerve Cells

• Neurotransmitters (chemicals) are transferred from one neuron to the next at a synapse.

• At any synapse, the transmission is in only one direction.

o One neuron is the sending neuron.

o The other neuron is the receiving neuron.

o Neurons can either excite or inhibit the neural actions of other neurons. Nice pictures of a synapse are available at:

http://www.rnceus.com/meth/Introneurotrans.html

and http://www.educarer.com/brain.htm .

Image downloaded from Wikipedia (1/9/07):http://en.wikipedia.org/wiki/Synapse

Action Potentials are All-of-None

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Action Potentials: Electrochemical waves that pass down the axon of a neuron.

• Action potentials are all-or-nothing.

• The rate of action potentials matters. The resting rate is not zero.

• The size is the same for all action potentials.

Psych 355, Miyamoto, Spr '15

Diagram Shows the Time of Occurrence of an Action Potential (Spike)

Time

Summary re Neural Signals

Summary re Neural Signals

• Information is carried by the firing rate of a neuron, not the size of an action potential (all are of equal size).

• Inputs to a neuron can increase (excite) or decrease (inhibit)the firing rate of the neuron.

• The signal is transmitted from one neuron to the nextby means of neurotransmitter chemicals that are passed from one neuron to another at the synapse.

Psych 355, Miyamoto, Spr '15 17Single Cell Recordings

Single Cell Recordings

• The firing rate of individual neurons is measured by means of single cell recordings.

• Today it is possible to record simultaneously from a number of of individual cells.

Psych 355, Miyamoto, Spr '15 18Strengths and Weaknesses of Single Cell Recordings

Strengths and Weaknesses of Single Cell Recording Methods

Strengths

• Excellent spatial information – the scientist has a very good idea where the recording is located in the brain.

• Excellent temporal information – the scientist knows when the neuron fires to a high level of precision.

Drawbacks

• Practically difficult to record from more than a small number of cells at a given time, e.g., 15 to 20 cells simultaneously.

• The method is very invasive.

Psych 355, Miyamoto, Spr '15 19Event-Related Potentials (ERP’s)

Event-Related Potentials (ERP’s)

• Measures electrical potentials on the scalp while processing a stimulus.

Psych 355, Miyamoto, Spr '15 20Strengths and Weaknesses of ERP’s

Event-Related Potentials (ERP’s)

• Strengths and weaknesses of ERP’s as research tool. ♦ Poor spatial resolution. ♦ Excellent temporal resolution. ♦ Relatively non-invasive. ♦ Sketchy understanding of the brain processes

that are producing the EEG signal.

Psych 355, Miyamoto, Spr '15 21Functional Magnetic Resonance Imaging (fMRI)

Psych 355, Miyamoto, Spr '15 22

Friday, April 03, 2015: The Lecture Ended Here